login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A200977 Smallest number expressible in the form a^2 + 2b^2, with positive integers a and b, in exactly n ways. 0
3, 27, 99, 297, 891, 1683, 8019, 5049, 18513, 15147, 649539, 31977, 314721, 136323, 166617, 95931, 10673289, 351747, 64304361, 287793, 1499553, 8450649, 127680201, 863379, 20160657, 99379467, 5979699, 5180274, 1235641473, 3165723, 50984802, 3933171 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Incidentally all terms are multiples of 3.
LINKS
EXAMPLE
3 = 1+2*1^2.
27 = 3+2*3^2 = 5^2+2*1^2.
99 = 1+2*7^2 = 7^2+2*5^2 = 9^2+2*3^2.
CROSSREFS
Cf. A154777 (numbers of the form a^2 + 2b^2 with positive integers a, b).
Sequence in context: A318908 A343135 A343105 * A302525 A303407 A173491
KEYWORD
nonn
AUTHOR
Zak Seidov, Nov 29 2011
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 09:59 EDT 2024. Contains 371268 sequences. (Running on oeis4.)